Epoxy resins are widely employed in wind turbine blades,drone rotors,and automotive interiors due to their excel-lent mechani-cal proper-ties and long service life.However,their insoluble and infusible cross-linked ne...Epoxy resins are widely employed in wind turbine blades,drone rotors,and automotive interiors due to their excel-lent mechani-cal proper-ties and long service life.However,their insoluble and infusible cross-linked networks pose a significant re-cycling challenge,particularly with the impending retirement of the first generation of wind turbine blades.In this work,we reported a fully bio-based epoxy Vitrimer(FEP)incorporat-ing a dual-dynamic covalent network design and systematically investigated the influence of the 1,5,7-triazabicyclo[4.4.0]dec-5-ene(TBD)catalyst on its curing kinetics,thermal/mechan-ical properties,dynamic exchange behavior,and degradation performance in a mild alkaline solution.Compared to conventional epoxy resins,FEP exhibited superior tensile strength and elongation at break at an optimal TBD concentration(2 wt%),achieving an excellent strength-toughness balance.The presence of TBD accelerated the exchange rates of both disulfide and ester bonds,endowing FEP with notable stress relaxation at elevated tempera-tures.Moreover,FEP demonstrated complete dissolution in 1 mol/L NaOH within 6 h at 25℃.These results underscored the exceptional strength,toughness,and recyclability of FEP,positioning it as a promising,environmentally friendly matrix resin for next-generation appli-cations in the new energy sector.展开更多
Ocean-degradable polyesters incorporating hydrophilic and rapidly degradable glycolide(GL)units into the polymer chain are the most promising for addressing marine plastic pollution,however,it is challenging to obtain...Ocean-degradable polyesters incorporating hydrophilic and rapidly degradable glycolide(GL)units into the polymer chain are the most promising for addressing marine plastic pollution,however,it is challenging to obtain high-molecular-weight copolymers with narrow molecular weight distributions.Herein,we prepared a novel biodegradable material,poly(butylene succinate-co-glycolide)(PBSGL),through ring-opening copolymerization using glycolide,succinic anhydride,and 1,4-butanediol as raw materials,providing a new solution strategy for marine pollution.GL could be polymerized according to the pre-designed composition by 1H-nuclear magnetic resonance(1H-NMR)and gel permeation chromatography(GPC)results,indicating controlled polymerization with the synthesized PBSGLs having a weight-average molecular weight of up to 12.30×10^(4) g/mol and a narrow molecular weight distribution(1.33–1.65).Differential scanning calorimeter(DSC)and thermogravimetric analysis(TGA)results showed that T_(g) of PBSGLs increased from−32.5°C to−26.5°C with the increase of GL content from 0%to 40%,while T_(m)(>76°C)was much lower than T_(d,5%)(>314°C),which indicated that PBSGLs had good thermal stability and expanded the processing window and application range of the original poly(butylene succinate)(PBS)materials.Under simulated difficult conditions,PBSGL copolyesters could degrade faster with increasing GL content,where PBSGL40 degraded by 22.6%in 12 days,showing good biodegradability.Currently,most biodegradable polyesters with good performance slowly degrade in seawater.In a 30-day artificial seawater degradation test,the amorphous PBSGL40 copolyester showed a about 15-fold(2.33%weight loss)improvement in degradation ability compared to pure PBS,demonstrating rapid seawater degradation capability.展开更多
The structural design and performance characteristics of the diaphragm have a decisive impact on the safety and electrochemical performance of lithium-ion batteries(LIBs).However,traditional polyolefin diaphragms stil...The structural design and performance characteristics of the diaphragm have a decisive impact on the safety and electrochemical performance of lithium-ion batteries(LIBs).However,traditional polyolefin diaphragms still face challenges in simultaneously improving the ion transport efficiency and thermal stability.Here,we report an in situ dynamic lithium compensation strategy for manufacturing a biobased furan aramid/ceramic diaphragm(BAS)with higher thermal stability and ion transport efficiency.Specifically,exchangeable carboxyl groups(–COOH)are introduced into the bio-based furan aramid(BA)framework,which are in situ converted into–COOLi groups to form lithium ions(Li^(+))transport channels,achieving dynamic compensation of active Li^(+).The dual transmission system of ion exchange and physical pore channels synergistically enhances the ionic conductivity of BAS to 1.536 mS cm^(-1).The high polarity structure of the furan ring and the electrolyte have excellent compatibility,significantly reducing the solid–liquid interfacial energy,making BAS have extremely high electrolyte wettability(contact angle of 0°).The BA amide group forms a multi-scale bonding network with the nano-ceramics.The BAS prepared by the water-coating process exhibits excellent thermal stability(with a thermal shrinkage rate of less than 1%after 1 h at 150℃).The LiFePO_(4)|Li half-cell assembled with BAS shows a capacity retention rate of up to 91.7%after 280 cycles at 1C,with a Coulomb efficiency of 99%,demonstrating excellent cycling stability.This design and development based on bio-materials provides a new approach for high safety and high energy density battery systems.展开更多
Developing green and efficient methods to acquire lignocellulose-based chemicals with high added value is beneficial for facilitating green chemistry and sustainable development.The goal of this study is to demonstrat...Developing green and efficient methods to acquire lignocellulose-based chemicals with high added value is beneficial for facilitating green chemistry and sustainable development.The goal of this study is to demonstrate that bio-based benzaldehyde,a noteworthy high-value chemical,is able to be directionally prepared from lignocellulosic biomass.This new control-lable transformation was materialized by uniting catalytic-pyrolysis of lignocellulose to toluene intermediate and catalytic oxidation of toluene intermediate to bio-based benzalde-hyde.This work also developed a highly active magnetic catalyst(CoFe_(2)O_(4)@Biochar(HTR)),achieving 77.1%benzaldehyde selectivity and 46.7%benzaldehyde yield using this catalyst.It was found that introducing the biochar carrier into the cobalt iron composite metal oxide cat-alyst enhanced hydroxyl radical formation and bio-based benzaldehyde synthesis.Based on catalyst characterizations and hydroxyl radical analysis,potential reaction mechanism for bio-based benzaldehyde synthesis was proposed.This strategy may provide a beneficial pathway for developing high-value bio-based chemical(benzaldehyde)using renewable lignocellulosic biomass.展开更多
The thermotropic liquid crystal polyester(TLCP)fiber is an increasingly important strategic high-performance fiber.In this paper,the TLCP was prepared by two-step melt polymerization using 4-hydroxybenzoic acid(HBA)an...The thermotropic liquid crystal polyester(TLCP)fiber is an increasingly important strategic high-performance fiber.In this paper,the TLCP was prepared by two-step melt polymerization using 4-hydroxybenzoic acid(HBA)and 6-hydroxy-2-naphthoic acid(HNA)as comonomers at a molar ratio of 7∶3.The structure of TLCP was confirmed by the Fourier transform infrared(FTIR)spectrometer and nuclear magnetic resonance(NMR)spectrometer.The thermal and rheological properties of TLCP before and after heat treatment were analyzed systematically by the differential scanning calorimeter(DSC),dynamic mechanical analyzer(DMA)and high-temperature rotational rheometer.The results revealed that the melting temperature,glass transition temperature and melt viscosity of the TLCP increased significantly after heat treatment.It indicates that the crystallization of the TLCP is perfect,and solid-phase condensation occurs during heat treatment,which increases its molecular mass.In conclusion,heat treatment at a temperature below but close to the melting temperature can effectively regulate the structure and properties of the TLCP,and the results of this study can provide a reference for the high strengthening of TLCP fibers.展开更多
With the escalating global emphasis on environmental conservation and sustainable development,enhancing the service quality and durability of road surfaces and facilitating the green development of highways have comma...With the escalating global emphasis on environmental conservation and sustainable development,enhancing the service quality and durability of road surfaces and facilitating the green development of highways have commanded considerable attention.Bio-based polyurethane,on account of its remarkable physical and chemical properties,green,sustainable and renewable capacity,as well as its structural design capabilities,has drawn widespread attention and numerous studies have been carried out.It has gradually started to substitute traditional petroleum-based polyurethane materials in road engineering.Nevertheless,the application of bio-based polyurethane materials in road engineering remains in the exploratory phase.To stimulate the application research of bio-based polyurethane materials in road engineering and offer additional research directions,this paper reviews the research advancements of bio-based polyurethane materials and their applications in road engineering.The fundamental classification of bio-based polyurethane is introduced.The characteristics and challenges associated with various preparation methods for bio-based polyurethane are described.The influence of bio-based polyurethane on road engineering materials are analyzed.The evaluation indicators of bio-based polyurethane within the life cycle of road engineering are investigated.Finally,the development tendency towards in road engineering applications are forecasted.This paper provides a reference for the study of bio-based polyurethane materials in road engineering applications.展开更多
Chemical modification of polymers represents a pivotal method for achieving functionalized polymer materials.However,due to the lack of post-functional handle,the chemical modification of polyester materials remains a...Chemical modification of polymers represents a pivotal method for achieving functionalized polymer materials.However,due to the lack of post-functional handle,the chemical modification of polyester materials remains a significant challenge.Ring-opening copolymerization of cyclic anhydride and epoxides is a powerful approach to synthesize polyesters.In this work,we for the first time demonstrate the functionalizability of polyesters synthesized with brominated anhydride monomers.The post-functionalization is amenable to a wide variety of reactive groups and reactions with high yields.With multiple well-established functionalization pathways of brominated polyester materials and optimized the conditions for the modification reactions,a series of functionalized polyester materials can be obtained with high yields,providing new insights for the research about functionalization of polymers.展开更多
The current global shortage of oil resources and the pollution problems caused by traditional barrier materials urgently require the search for new substitutes.Biodegradable bio-based barrier materials possess the cha...The current global shortage of oil resources and the pollution problems caused by traditional barrier materials urgently require the search for new substitutes.Biodegradable bio-based barrier materials possess the characteristics of being renewable,environmentally friendly,and having excellent barrier properties.They have become an important choice in fields such as food packaging,agricultural film covering,and medical protection.This review systematically analyzes the design and research of this type of material,classifying biobased and biodegradable barrier materials based on the sources of raw materials and synthesis pathways.It also provides a detailed introduction to the latest research progress of biobased and biodegradable barrier materials,discussing the synthesis methods and improvement measures of their barrier properties.Subsequently,it analyzes the related technologies for enhancing the barrier properties of biobased and biodegradable barrier materials,and finally looks forward to the directions that future research should focus on,promoting the transition of biobased and biodegradable barrier materials from the laboratory to industrial applications.展开更多
The asymmetric alternating copolymerization of meso-epoxide and cyclic anhydrides provides an efficient access to enantiopure polyesters.Contrary to the extensive investigation of the stereochemistry resulting from ep...The asymmetric alternating copolymerization of meso-epoxide and cyclic anhydrides provides an efficient access to enantiopure polyesters.Contrary to the extensive investigation of the stereochemistry resulting from epoxide building block,the chirality from anhydride and the configurational match with epoxide remain elusive.Herein,we discover that the bimetallic chromium catalysts have led to an obvious enhancement in terms of reactivity and enantioselectivity for the asymmetric copolymerization of meso-epoxide with various non-symmetric chiral anhydrides.Up to 97%ee was obtained during the asymmetric copolymerization of cyclohexene oxide(CHO)with(R)-methylsuccinic anhydride(R-MSA),and three-or four-carbon chiral centers were simultaneously installed in the aliphatic polyester backbone.In particular,the different combinations of stereochemistry in epoxide and anhydride building blocks considerably affect the thermal properties and crystalline behaviors of the resulting polyesters.This study uncovers an interesting method for regulating polymer crystallinity via matching the chirality of different monomers.展开更多
The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important.This work developed th...The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important.This work developed the bio-based electrotechnical epoxy resins based on magnolol.High-performance epoxy resin(DGEMT)with a double crosslinked points and its composites(Al_(2)O_(3)/DGEMT)were obtained taking advantages of the two bifunctional groups(allyl and phenolic hydroxyl groups)of magnolol.Benefitting from the distinctive structure of DGEMT,the Al_(2)O_(3)/DGEMT composites exhibited the advantages of intrinsically high thermal conductivity,high insulation,and low dielectric loss.The AC breakdown strength and thermal conductivity of Al_(2)O_(3)/DGEMT composites were 35.5 kV/mm and 1.19 W·m-1·K-1,respectively,which were 15.6%and 52.6%higher than those of petroleum-based composites(Al_(2)O_(3)/DGEBA).And its dielectric loss tanδ=0.0046 was 20.7%lower than that of Al_(2)O_(3)/DGEBA.Furthermore,the mechanical,thermal and processing properties of Al_(2)O_(3)/DGEMT are fully comparable to those of Al_(2)O_(3)/DGEBA.This work confirms the feasibility of manufacturing environmentally friendly power equipment using bio-based epoxy resins,which has excellent engineering applications.展开更多
By investigating the performance characteristics of the bio-based surfactant 8901A,a composite decontamination and injection system was developed using 8901A as the primary agent,tailored for application in low-permea...By investigating the performance characteristics of the bio-based surfactant 8901A,a composite decontamination and injection system was developed using 8901A as the primary agent,tailored for application in low-permeability and heavy oil reservoirs under varying temperature conditions.The results demonstrate that this system effectively reduces oil–water interfacial tension,achieving an ultra-low interfacial tension state.The static oil washing efficiency of oil sands exceeds 85%,the average pressure reduction rate reaches 21.55%,and the oil recovery rate improves by 13.54%.These enhancements significantly increase the system’s ability to dissolve oilbased blockages,thereby lowering water injection pressure caused by organic fouling,increasing the injection volume of injection wells,and ultimately improving oil recovery efficiency.展开更多
To enhance the properties of bio-based polyesters,enabling them to more closely mimic the characteristics of terephthalate-based materials,a series of aliphatic-aromatic copolyesters(P_(1)–P_(4))were synthesized via ...To enhance the properties of bio-based polyesters,enabling them to more closely mimic the characteristics of terephthalate-based materials,a series of aliphatic-aromatic copolyesters(P_(1)–P_(4))were synthesized via melt polycondensation.Diester monomers M and N were synthesized via the Williamson reaction,using lignin-derived 2-methoxyhydroquinone,methyl 4-chloromethylbenzoate,and methyl chloroacetate as starting materials.Hydroquinone bis(2-hydroxyethyl)ether(HQEE)and 1,4-cyclohexanedimethanol(CHDM)were employed as cyclic segments,while 1,4-butanediol(BDO)and 1,6-hexanediol(HDO)served as alkyl segments within the copolymer structures.The novel copolyesters exhibited molecular weights(Mw)in the range of 5.25×10^(4)–5.87×10^(4) g/mol,with polydispersity indices spanning from 2.50–2.66.Evaluation of the structural and thermomechanical properties indicated that the inclusion of alkyl segments induced a reduction in both crystallinity and molecular weight,while significantly improving the flexibility,whereas cyclic segments enhanced the processability of the copolyesters.Copolyesters P_(1) and P_(2),due to the presence of rigid segments(HQEE and CHDM),displayed relatively high glass transition temperatures(Tg>80℃)and melting temperatures(Tm>170℃).Notably,P_(2),incorporating CHDM,exhibited superior elongation properties(272%),attributed to the enhanced chain mobility resulting from its trans-conformation,while P_(1) was found to be likely brittle owing to excessive chain stiffness.Biodegradability assessment using earthworms as bioindicators revealed that the copolyesters demonstrated moderate degradation profiles,with P_(2) exhibiting a degradation rate of 4.82%,followed by P_(4) at 4.07%,P_(3) at 3.65%,and P_(1) at 3.17%.The higher degradation rate of P_(2) was attributed to its relatively larger d-spacing and lower toxicity,which facilitated enzymatic hydrolytic attack by microorganisms.These findings highlight the significance of optimizing the structural chain segments within aliphatic-aromatic copolyesters.By doing so,it is possible to significantly enhance their properties and performance,offering viable bio-based alternatives to petroleum-based polyesters such as polyethylene terephthalate(PET).展开更多
Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)...Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)and internal factors such as binder composition.Although laboratory simulations of aging are well established for conventional bituminous binders,limited attention has been paid to replicating and evaluating aging processes in bio-based binders.This review provides a comprehensive analysis of current laboratory techniques for simulating and assessing binder aging,with a focus on two key areas:aging simulation protocols and evaluation methodologies.The analysis shows that although several efforts have been made to incorporate external aging factors into lab simulations,significant challenges persist,especially in the case of bio-based binders,which are characterized by a high variability in composition and limited understanding of their aging behavior.Current evaluation approaches also exhibit limitations.Improvements are needed in the molecular-level analysis of oxidation(e.g.,through more representative oxidation modelsin molecular dynamicssimulations),in the separation and quantification of binder constituents,and in the application of advanced techniques such as fluorescence microscopy to better characterize polymer dispersion.To enhance the reliability of laboratory simulations,future research should aim to improve the correlation between laboratory and field aging,define robust aging indexes,and refine characterization methods.These advancements are particularly critical for bio-based binders,whose performance is highly sensitive to aging and for which standard test protocols are still underdeveloped.A deeper understanding of aging mechanisms in both polymer-modified and biobased binders,along with improved analytical tools for assessing oxidative degradation and morphological changes,will be essential to support the development of sustainable,high-performance paving materials.展开更多
In the context of transitioning toward more sustainable construction materials,this study explores the impact of incorporating millet husks as an alternative to sand on the physical,mechanical,and thermal performance ...In the context of transitioning toward more sustainable construction materials,this study explores the impact of incorporating millet husks as an alternative to sand on the physical,mechanical,and thermal performance of lightweight concrete.Through a mixture design approach,five formulations were selected and thoroughly characterized.The analysis of iso-response curves enabled an in-depth assessment of the cross-effects between formulation parameters and their interactions on the final properties of the material.The results show that integrating millet husks leads to a significant reduction in density,reaching up to 21%,while maintaining notable mechanical performance.A balanced formulation of sand and fibers achieved a maximum compressive strength of 12.11 MPa,demonstrating that,under specific conditions,plant fibers actively contribute to the structural integrity of the composite.In tensile strength,the positive influence of fibers is even more pronounced,with a maximum resistance of 8.62 MPa,highlighting their role in enhancing material cohesion.From a thermal perspective,millet husks reduce both thermal conductivity and effusivity,thereby limiting heat transfer and accumulation within the composite.Iso-response curve analysis reveals that these effects are directly linked to the proportions of the constituents and that achieving an optimal balance between sand,fibers,and cement is key to maximizing performance.These findings demonstrate that the adopted approach allows moving beyond conventional substitution methods by identifying optimal configurations for the design of lightweight bio-based concretes that are both strong and insulating,thereby confirming the potential of millet husks in developing lightweight concretes suitable for sustainable construction applications.展开更多
Aliphatic polyesters and polycarbonates are among the promising sustainable polymers,which exhibit unique degradability and chain-chain interactions owing to their heterofunctionality.However,monocomponent aliphatic p...Aliphatic polyesters and polycarbonates are among the promising sustainable polymers,which exhibit unique degradability and chain-chain interactions owing to their heterofunctionality.However,monocomponent aliphatic polyesters and polycarbonates usually suffer from inferior properties and functionalities.By contrast,precisely modulated block copolymers composed of polyesters and polycarbonates give rise to sustainable materials with tailored performance.An efficient approach to synthesize the block copolymers is the ring-opening(co)polymerization of the heterocycle monomers.Herein,this review presents the heterocycle monomer ring-opening(co)polymerization for the formation of sequence-controlled block polyesters and polycarbonates.Available synthetic strategies,different monomers,monomer combinations and the catalyst systems for the formation of different block polyesters and polycarbonates are summarized.展开更多
An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthrolin...An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthroline/bipyridine,and poly-F substituted phenyl ligands as the mixture linkers.The results of control experiments and theoretical calculations reveal that the–F on the phenyl linkers efficiently tunes the electron-deficient nature of Pd through the Zr_(6) clusters bridges,which favors the adsorption and activation of the furan ring.Furthermore,the conjugation of different nitrogen-containing ligands facilitates Pd coordination for the Heck-type insertion and subsequent electrophilic palladation,respectively.As a result,the oxidative arylation of FA derivatives is substantially enhanced because of these electronic and steric synergistic effects.Under the optimized conditions,72.2%FA conversion and 74.8%mono aryl furan(MAF)selectivity are shown in the Heck-type insertion.Meanwhile,85.3%of MAF is converted,affording 74.8%selectivity of final product(AFs)in the subsequent electrophilic palladation reaction.This process efficiency is remarkably higher than that with homogeneous catalysts.In addition,furan-benzene polymer obtained from the halogen-free synthesis catalyzed by UiO-67-Pd(F)show significantly better properties than that from conventional Suzuki coupling method.Therefore,the present work provides a new insight for useful AFs synthesis by oxidative arylation of bio-furan via rational tunning the metal center micro-environment of heterogeneous catalyst.展开更多
This study proposes to use the unconfined compressive strength(UCS)and the bender element(BE)tests for determining the strength and the initial small-strain shear modulus of Bangkok soft marine clay improved by cement...This study proposes to use the unconfined compressive strength(UCS)and the bender element(BE)tests for determining the strength and the initial small-strain shear modulus of Bangkok soft marine clay improved by cement and polyester fibers.This study varies the content of admixed cement(1%–20%)and polyester fibers(0–20%),including the curing time(3–28 d)for preparing 360 samples.Moreover,this study uses the Michaelis-Menten kinetics concept to model cement hydration saturation.From the study,it is concluded as follows.The modelled results reveals that at least 10%cement and 1%polyester fiber are recommended to attain the 28-d UCS standards(294 kPa)for highway subgrade materials in Thailand.This also fulfils sustainable construction due to reducing normal-use cement from 20%to 10%.Unfortunately,the addition of polyester fibers into the Bangkok clay with at least 5%cement reduces shear modulus by 1.12–1.32 times.The Abram's relationship between shear modulus and the mixing-water-to-cement ratio is found time-dependent.From the composite theory,the BE detects the polyester fiber zone as a defect in the Bangkok clay(matrix)with 5%–20%cement.So,the 28-d shear modulus in the polyester fiber zone is negative(up to0.034 MPa for 20%fiber),similar to softening phenomenon in concrete cracking(negative stiffness).For the 28-d shear modulus of fiber zone,the optimum cement content is around 2%for the positive influences of polyester fibers.Experimentally,the timedependent normalized UCS for 10%and 20%cement is compatible with other studies,and its development rate increases with the cement content as 0.3017,0.3172 and 0.3204 for 5%,10%and 20%cement,respectively.The 28-d relationship between shear modulus and UCS shows that low-cement soft clay requires high polyester fiber content(5%–20%)to activate UCS improvement.However,the soft clay with enough cement(20%)causes the uniformly distributed UCS improvement.展开更多
A series of novel thermotropic liquid crystalline polyesters bearing nonlinear optical azobenzene side group were synthesized by high temperature solution polycondensation and their structures,thermal stability, phas...A series of novel thermotropic liquid crystalline polyesters bearing nonlinear optical azobenzene side group were synthesized by high temperature solution polycondensation and their structures,thermal stability, phase transition behavior and crystallinity were characterized by IR,elemental analysis, TG-DTA, polarizing optical microscope (POM) equipped with a hot stage and X-ray diffraction techniques. The results demonstrate that all the synthesized polyesters exhibit nematic liquid crystalline phases and show relatively high glass transition temperatures and good thermal stability.展开更多
Renewable 2,5-furandicarboxylic acid-based polyesters are one of the most promising materials for achieving plastic replacement in the age of energy and environmental crisis.However,their properties still cannot compe...Renewable 2,5-furandicarboxylic acid-based polyesters are one of the most promising materials for achieving plastic replacement in the age of energy and environmental crisis.However,their properties still cannot compete with those of petrochemical-based plastics,owing to insufficient molecular and/or microstructure designs.Herein,we utilize the Ti_(3)C_(2)T_(x)-based MXene nanosheets for decorating carbon nanotube(CNT)and obtaining the structurally stable and highly dispersed dendritic heterostructured MXene@CNT,that can act as multi-roles,i.e.,polycondensation catalyst,crystal nucleator,and interface enhancer of polyester.The biobased MXene@CNT/polybutylene furandicarboxylate(PBF)(denoted as MCP)nanocomposites are synthesized by the strategy of“in situ catalytic polymerization and hot-pressing”.Benefiting from the multi-scale interactions(i.e.,covalent bonds,hydrogen bonds,and physical interlocks)in hybrid structure,the MCP presents exceptional mechanical strength(≈101 MPa),stiffness(≈3.1 GPa),toughness(≈130 MJ m^(-3)),and barrier properties(e.g.,O_(2)0.0187 barrer,CO_(2)0.0264 barrer,and H2O 1.57×10^(-14) g cm cm^(-2) s Pa)that are higher than most reported bio-based materials and engineering plastics.Moreover,it also displays satisfactory multifunctionality with high reprocessability(90%strength retention after 5 recycling),UV resistance(blocking 85%UVA rays),and solvent-resistant properties.As a state-of-art high-performance and multifunctional material,the novel bio-based MCP nanocomposite offers a more sustainable alternative to petrochemical-based plastics in packaging and engineering material fields.More importantly,our catalysis-interfacial strengthening integration strategy opens a door for designing and constructing high-performance bio-based polyester materials in future.展开更多
It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranc...It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranched toughener,carboxylic acid-functionalized tannic acid(CATA),was successfully prepared and applicated to the preparation of solvent-free epoxy resins.The mechanical performance,morphology,structural characterization,and thermal characterization of toughened epoxy resin system were studied.The toughened epoxy resin system with only 1.0wt%CATA reached the highest impact strength,111%higher than the neat epoxy resin system.Notably,the tensile strength and elongation at break of toughened epoxy resin systems increased moderately with increasing CATA loading.Nonphase-separated hybrids with significant toughening effect were obtained.Additionally,the thermal stabilities of toughened epoxy resin systems decreased with increasing CATA loading.This study provides an eco-friendly,cost-effective,and facile approach for the preparation of high-performance,solvent-free epoxy resins with potential for practical applications in sealing integrated circuits and electrical devices fields.展开更多
基金support from the National Natural Science Foundation of China(Nos.22293011,T2341001)the Major Science and Technology Project of Anhui Province(202203a06020010).
文摘Epoxy resins are widely employed in wind turbine blades,drone rotors,and automotive interiors due to their excel-lent mechani-cal proper-ties and long service life.However,their insoluble and infusible cross-linked networks pose a significant re-cycling challenge,particularly with the impending retirement of the first generation of wind turbine blades.In this work,we reported a fully bio-based epoxy Vitrimer(FEP)incorporat-ing a dual-dynamic covalent network design and systematically investigated the influence of the 1,5,7-triazabicyclo[4.4.0]dec-5-ene(TBD)catalyst on its curing kinetics,thermal/mechan-ical properties,dynamic exchange behavior,and degradation performance in a mild alkaline solution.Compared to conventional epoxy resins,FEP exhibited superior tensile strength and elongation at break at an optimal TBD concentration(2 wt%),achieving an excellent strength-toughness balance.The presence of TBD accelerated the exchange rates of both disulfide and ester bonds,endowing FEP with notable stress relaxation at elevated tempera-tures.Moreover,FEP demonstrated complete dissolution in 1 mol/L NaOH within 6 h at 25℃.These results underscored the exceptional strength,toughness,and recyclability of FEP,positioning it as a promising,environmentally friendly matrix resin for next-generation appli-cations in the new energy sector.
基金financially supported by the National Natural Science Foundation of China (No. 52203012)Shanghai Rising-Star Program (No. 23QC1400900).
文摘Ocean-degradable polyesters incorporating hydrophilic and rapidly degradable glycolide(GL)units into the polymer chain are the most promising for addressing marine plastic pollution,however,it is challenging to obtain high-molecular-weight copolymers with narrow molecular weight distributions.Herein,we prepared a novel biodegradable material,poly(butylene succinate-co-glycolide)(PBSGL),through ring-opening copolymerization using glycolide,succinic anhydride,and 1,4-butanediol as raw materials,providing a new solution strategy for marine pollution.GL could be polymerized according to the pre-designed composition by 1H-nuclear magnetic resonance(1H-NMR)and gel permeation chromatography(GPC)results,indicating controlled polymerization with the synthesized PBSGLs having a weight-average molecular weight of up to 12.30×10^(4) g/mol and a narrow molecular weight distribution(1.33–1.65).Differential scanning calorimeter(DSC)and thermogravimetric analysis(TGA)results showed that T_(g) of PBSGLs increased from−32.5°C to−26.5°C with the increase of GL content from 0%to 40%,while T_(m)(>76°C)was much lower than T_(d,5%)(>314°C),which indicated that PBSGLs had good thermal stability and expanded the processing window and application range of the original poly(butylene succinate)(PBS)materials.Under simulated difficult conditions,PBSGL copolyesters could degrade faster with increasing GL content,where PBSGL40 degraded by 22.6%in 12 days,showing good biodegradability.Currently,most biodegradable polyesters with good performance slowly degrade in seawater.In a 30-day artificial seawater degradation test,the amorphous PBSGL40 copolyester showed a about 15-fold(2.33%weight loss)improvement in degradation ability compared to pure PBS,demonstrating rapid seawater degradation capability.
基金the financial support from the National Natural Science Foundation of China(22293011,T2341001)the Major Science and Technology Project of Anhui Province(202203a06020010)+1 种基金the Horizontal Project Provided by Jiangsu Zhuogao New Materials Technology Co.,Ltd.(Td00923003H)Joint Laboratory by China Power Investment Ronghe New Energy Technology Co.,Ltd.and the Central Government Guiding Special Fund Project for Local Science and Technology Development(202407a12020008)。
文摘The structural design and performance characteristics of the diaphragm have a decisive impact on the safety and electrochemical performance of lithium-ion batteries(LIBs).However,traditional polyolefin diaphragms still face challenges in simultaneously improving the ion transport efficiency and thermal stability.Here,we report an in situ dynamic lithium compensation strategy for manufacturing a biobased furan aramid/ceramic diaphragm(BAS)with higher thermal stability and ion transport efficiency.Specifically,exchangeable carboxyl groups(–COOH)are introduced into the bio-based furan aramid(BA)framework,which are in situ converted into–COOLi groups to form lithium ions(Li^(+))transport channels,achieving dynamic compensation of active Li^(+).The dual transmission system of ion exchange and physical pore channels synergistically enhances the ionic conductivity of BAS to 1.536 mS cm^(-1).The high polarity structure of the furan ring and the electrolyte have excellent compatibility,significantly reducing the solid–liquid interfacial energy,making BAS have extremely high electrolyte wettability(contact angle of 0°).The BA amide group forms a multi-scale bonding network with the nano-ceramics.The BAS prepared by the water-coating process exhibits excellent thermal stability(with a thermal shrinkage rate of less than 1%after 1 h at 150℃).The LiFePO_(4)|Li half-cell assembled with BAS shows a capacity retention rate of up to 91.7%after 280 cycles at 1C,with a Coulomb efficiency of 99%,demonstrating excellent cycling stability.This design and development based on bio-materials provides a new approach for high safety and high energy density battery systems.
基金supported by the National Natural Sci-ence Foundation of China(Nos.U21A20288 and 21978280).
文摘Developing green and efficient methods to acquire lignocellulose-based chemicals with high added value is beneficial for facilitating green chemistry and sustainable development.The goal of this study is to demonstrate that bio-based benzaldehyde,a noteworthy high-value chemical,is able to be directionally prepared from lignocellulosic biomass.This new control-lable transformation was materialized by uniting catalytic-pyrolysis of lignocellulose to toluene intermediate and catalytic oxidation of toluene intermediate to bio-based benzalde-hyde.This work also developed a highly active magnetic catalyst(CoFe_(2)O_(4)@Biochar(HTR)),achieving 77.1%benzaldehyde selectivity and 46.7%benzaldehyde yield using this catalyst.It was found that introducing the biochar carrier into the cobalt iron composite metal oxide cat-alyst enhanced hydroxyl radical formation and bio-based benzaldehyde synthesis.Based on catalyst characterizations and hydroxyl radical analysis,potential reaction mechanism for bio-based benzaldehyde synthesis was proposed.This strategy may provide a beneficial pathway for developing high-value bio-based chemical(benzaldehyde)using renewable lignocellulosic biomass.
基金National Key Research and Development Program of China (No.2021YFB3700105)。
文摘The thermotropic liquid crystal polyester(TLCP)fiber is an increasingly important strategic high-performance fiber.In this paper,the TLCP was prepared by two-step melt polymerization using 4-hydroxybenzoic acid(HBA)and 6-hydroxy-2-naphthoic acid(HNA)as comonomers at a molar ratio of 7∶3.The structure of TLCP was confirmed by the Fourier transform infrared(FTIR)spectrometer and nuclear magnetic resonance(NMR)spectrometer.The thermal and rheological properties of TLCP before and after heat treatment were analyzed systematically by the differential scanning calorimeter(DSC),dynamic mechanical analyzer(DMA)and high-temperature rotational rheometer.The results revealed that the melting temperature,glass transition temperature and melt viscosity of the TLCP increased significantly after heat treatment.It indicates that the crystallization of the TLCP is perfect,and solid-phase condensation occurs during heat treatment,which increases its molecular mass.In conclusion,heat treatment at a temperature below but close to the melting temperature can effectively regulate the structure and properties of the TLCP,and the results of this study can provide a reference for the high strengthening of TLCP fibers.
基金supported by the Key R&D Project in Shaanxi Province(No.2024GX-YBXM-371)Shaanxi Qinchuangyuan Scientists+Engineers Team Construction Project(2025QCY-KXJ-141).
文摘With the escalating global emphasis on environmental conservation and sustainable development,enhancing the service quality and durability of road surfaces and facilitating the green development of highways have commanded considerable attention.Bio-based polyurethane,on account of its remarkable physical and chemical properties,green,sustainable and renewable capacity,as well as its structural design capabilities,has drawn widespread attention and numerous studies have been carried out.It has gradually started to substitute traditional petroleum-based polyurethane materials in road engineering.Nevertheless,the application of bio-based polyurethane materials in road engineering remains in the exploratory phase.To stimulate the application research of bio-based polyurethane materials in road engineering and offer additional research directions,this paper reviews the research advancements of bio-based polyurethane materials and their applications in road engineering.The fundamental classification of bio-based polyurethane is introduced.The characteristics and challenges associated with various preparation methods for bio-based polyurethane are described.The influence of bio-based polyurethane on road engineering materials are analyzed.The evaluation indicators of bio-based polyurethane within the life cycle of road engineering are investigated.Finally,the development tendency towards in road engineering applications are forecasted.This paper provides a reference for the study of bio-based polyurethane materials in road engineering applications.
基金financially supported by the National Key R&D Program of China(No.2021YFA1501700)the Science and Technology Development Plan of Jilin Province(Nos.20230101042JC and 20210201059GX)+1 种基金the National Natural Science Foundation of China,Basic Science Center Program(No.51988102)the National Natural Science Foundation of China(Nos.52203017 and 52073272)。
文摘Chemical modification of polymers represents a pivotal method for achieving functionalized polymer materials.However,due to the lack of post-functional handle,the chemical modification of polyester materials remains a significant challenge.Ring-opening copolymerization of cyclic anhydride and epoxides is a powerful approach to synthesize polyesters.In this work,we for the first time demonstrate the functionalizability of polyesters synthesized with brominated anhydride monomers.The post-functionalization is amenable to a wide variety of reactive groups and reactions with high yields.With multiple well-established functionalization pathways of brominated polyester materials and optimized the conditions for the modification reactions,a series of functionalized polyester materials can be obtained with high yields,providing new insights for the research about functionalization of polymers.
基金supported by the Science and Technology Research Project of Henan Province(222102230031)Key Scientific Research Projects of Colleges and Universities in Henan Province(23A430018)Natural Science Foundation of Henan(252300420267).
文摘The current global shortage of oil resources and the pollution problems caused by traditional barrier materials urgently require the search for new substitutes.Biodegradable bio-based barrier materials possess the characteristics of being renewable,environmentally friendly,and having excellent barrier properties.They have become an important choice in fields such as food packaging,agricultural film covering,and medical protection.This review systematically analyzes the design and research of this type of material,classifying biobased and biodegradable barrier materials based on the sources of raw materials and synthesis pathways.It also provides a detailed introduction to the latest research progress of biobased and biodegradable barrier materials,discussing the synthesis methods and improvement measures of their barrier properties.Subsequently,it analyzes the related technologies for enhancing the barrier properties of biobased and biodegradable barrier materials,and finally looks forward to the directions that future research should focus on,promoting the transition of biobased and biodegradable barrier materials from the laboratory to industrial applications.
基金financially supported by the National Natural Science Foundation of China(Nos.22071016 and 21920102006)。
文摘The asymmetric alternating copolymerization of meso-epoxide and cyclic anhydrides provides an efficient access to enantiopure polyesters.Contrary to the extensive investigation of the stereochemistry resulting from epoxide building block,the chirality from anhydride and the configurational match with epoxide remain elusive.Herein,we discover that the bimetallic chromium catalysts have led to an obvious enhancement in terms of reactivity and enantioselectivity for the asymmetric copolymerization of meso-epoxide with various non-symmetric chiral anhydrides.Up to 97%ee was obtained during the asymmetric copolymerization of cyclohexene oxide(CHO)with(R)-methylsuccinic anhydride(R-MSA),and three-or four-carbon chiral centers were simultaneously installed in the aliphatic polyester backbone.In particular,the different combinations of stereochemistry in epoxide and anhydride building blocks considerably affect the thermal properties and crystalline behaviors of the resulting polyesters.This study uncovers an interesting method for regulating polymer crystallinity via matching the chirality of different monomers.
基金supported by the China Postdoctoral Science Foundation(No.2023M743622)Natural Science Foundation of Ningbo City(No.2024J109)+2 种基金National Natural Science Foundation of China(Nos.E52307038 and U23A20589)Ningbo 2025 Key Scientific Research Programs(Nos.2022Z111,2022Z160 and 2022Z198)the Leading Innovativeand Entrepreneur Team Introduction Program of Zhejiang(No.2021R01005).
文摘The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important.This work developed the bio-based electrotechnical epoxy resins based on magnolol.High-performance epoxy resin(DGEMT)with a double crosslinked points and its composites(Al_(2)O_(3)/DGEMT)were obtained taking advantages of the two bifunctional groups(allyl and phenolic hydroxyl groups)of magnolol.Benefitting from the distinctive structure of DGEMT,the Al_(2)O_(3)/DGEMT composites exhibited the advantages of intrinsically high thermal conductivity,high insulation,and low dielectric loss.The AC breakdown strength and thermal conductivity of Al_(2)O_(3)/DGEMT composites were 35.5 kV/mm and 1.19 W·m-1·K-1,respectively,which were 15.6%and 52.6%higher than those of petroleum-based composites(Al_(2)O_(3)/DGEBA).And its dielectric loss tanδ=0.0046 was 20.7%lower than that of Al_(2)O_(3)/DGEBA.Furthermore,the mechanical,thermal and processing properties of Al_(2)O_(3)/DGEMT are fully comparable to those of Al_(2)O_(3)/DGEBA.This work confirms the feasibility of manufacturing environmentally friendly power equipment using bio-based epoxy resins,which has excellent engineering applications.
文摘By investigating the performance characteristics of the bio-based surfactant 8901A,a composite decontamination and injection system was developed using 8901A as the primary agent,tailored for application in low-permeability and heavy oil reservoirs under varying temperature conditions.The results demonstrate that this system effectively reduces oil–water interfacial tension,achieving an ultra-low interfacial tension state.The static oil washing efficiency of oil sands exceeds 85%,the average pressure reduction rate reaches 21.55%,and the oil recovery rate improves by 13.54%.These enhancements significantly increase the system’s ability to dissolve oilbased blockages,thereby lowering water injection pressure caused by organic fouling,increasing the injection volume of injection wells,and ultimately improving oil recovery efficiency.
基金financially supported by State Administration of Foreign Experts Affairs(SAFEA)through the High-End Foreign Expert Program(No.BG2021227001)postdoctoral funding from Wuhan University of Science and Technology(No.105008701)。
文摘To enhance the properties of bio-based polyesters,enabling them to more closely mimic the characteristics of terephthalate-based materials,a series of aliphatic-aromatic copolyesters(P_(1)–P_(4))were synthesized via melt polycondensation.Diester monomers M and N were synthesized via the Williamson reaction,using lignin-derived 2-methoxyhydroquinone,methyl 4-chloromethylbenzoate,and methyl chloroacetate as starting materials.Hydroquinone bis(2-hydroxyethyl)ether(HQEE)and 1,4-cyclohexanedimethanol(CHDM)were employed as cyclic segments,while 1,4-butanediol(BDO)and 1,6-hexanediol(HDO)served as alkyl segments within the copolymer structures.The novel copolyesters exhibited molecular weights(Mw)in the range of 5.25×10^(4)–5.87×10^(4) g/mol,with polydispersity indices spanning from 2.50–2.66.Evaluation of the structural and thermomechanical properties indicated that the inclusion of alkyl segments induced a reduction in both crystallinity and molecular weight,while significantly improving the flexibility,whereas cyclic segments enhanced the processability of the copolyesters.Copolyesters P_(1) and P_(2),due to the presence of rigid segments(HQEE and CHDM),displayed relatively high glass transition temperatures(Tg>80℃)and melting temperatures(Tm>170℃).Notably,P_(2),incorporating CHDM,exhibited superior elongation properties(272%),attributed to the enhanced chain mobility resulting from its trans-conformation,while P_(1) was found to be likely brittle owing to excessive chain stiffness.Biodegradability assessment using earthworms as bioindicators revealed that the copolyesters demonstrated moderate degradation profiles,with P_(2) exhibiting a degradation rate of 4.82%,followed by P_(4) at 4.07%,P_(3) at 3.65%,and P_(1) at 3.17%.The higher degradation rate of P_(2) was attributed to its relatively larger d-spacing and lower toxicity,which facilitated enzymatic hydrolytic attack by microorganisms.These findings highlight the significance of optimizing the structural chain segments within aliphatic-aromatic copolyesters.By doing so,it is possible to significantly enhance their properties and performance,offering viable bio-based alternatives to petroleum-based polyesters such as polyethylene terephthalate(PET).
文摘Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)and internal factors such as binder composition.Although laboratory simulations of aging are well established for conventional bituminous binders,limited attention has been paid to replicating and evaluating aging processes in bio-based binders.This review provides a comprehensive analysis of current laboratory techniques for simulating and assessing binder aging,with a focus on two key areas:aging simulation protocols and evaluation methodologies.The analysis shows that although several efforts have been made to incorporate external aging factors into lab simulations,significant challenges persist,especially in the case of bio-based binders,which are characterized by a high variability in composition and limited understanding of their aging behavior.Current evaluation approaches also exhibit limitations.Improvements are needed in the molecular-level analysis of oxidation(e.g.,through more representative oxidation modelsin molecular dynamicssimulations),in the separation and quantification of binder constituents,and in the application of advanced techniques such as fluorescence microscopy to better characterize polymer dispersion.To enhance the reliability of laboratory simulations,future research should aim to improve the correlation between laboratory and field aging,define robust aging indexes,and refine characterization methods.These advancements are particularly critical for bio-based binders,whose performance is highly sensitive to aging and for which standard test protocols are still underdeveloped.A deeper understanding of aging mechanisms in both polymer-modified and biobased binders,along with improved analytical tools for assessing oxidative degradation and morphological changes,will be essential to support the development of sustainable,high-performance paving materials.
文摘In the context of transitioning toward more sustainable construction materials,this study explores the impact of incorporating millet husks as an alternative to sand on the physical,mechanical,and thermal performance of lightweight concrete.Through a mixture design approach,five formulations were selected and thoroughly characterized.The analysis of iso-response curves enabled an in-depth assessment of the cross-effects between formulation parameters and their interactions on the final properties of the material.The results show that integrating millet husks leads to a significant reduction in density,reaching up to 21%,while maintaining notable mechanical performance.A balanced formulation of sand and fibers achieved a maximum compressive strength of 12.11 MPa,demonstrating that,under specific conditions,plant fibers actively contribute to the structural integrity of the composite.In tensile strength,the positive influence of fibers is even more pronounced,with a maximum resistance of 8.62 MPa,highlighting their role in enhancing material cohesion.From a thermal perspective,millet husks reduce both thermal conductivity and effusivity,thereby limiting heat transfer and accumulation within the composite.Iso-response curve analysis reveals that these effects are directly linked to the proportions of the constituents and that achieving an optimal balance between sand,fibers,and cement is key to maximizing performance.These findings demonstrate that the adopted approach allows moving beyond conventional substitution methods by identifying optimal configurations for the design of lightweight bio-based concretes that are both strong and insulating,thereby confirming the potential of millet husks in developing lightweight concretes suitable for sustainable construction applications.
基金supported by the National Natural Science Foundation of China,Fund for Distinguished Young Scholars(No.52325301)CAS Project for Young Scientists in Basic Research(YSBR-094)the National Natural Science Foundation of China,Basic Science Center Program(No.51988102).
文摘Aliphatic polyesters and polycarbonates are among the promising sustainable polymers,which exhibit unique degradability and chain-chain interactions owing to their heterofunctionality.However,monocomponent aliphatic polyesters and polycarbonates usually suffer from inferior properties and functionalities.By contrast,precisely modulated block copolymers composed of polyesters and polycarbonates give rise to sustainable materials with tailored performance.An efficient approach to synthesize the block copolymers is the ring-opening(co)polymerization of the heterocycle monomers.Herein,this review presents the heterocycle monomer ring-opening(co)polymerization for the formation of sequence-controlled block polyesters and polycarbonates.Available synthetic strategies,different monomers,monomer combinations and the catalyst systems for the formation of different block polyesters and polycarbonates are summarized.
文摘An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthroline/bipyridine,and poly-F substituted phenyl ligands as the mixture linkers.The results of control experiments and theoretical calculations reveal that the–F on the phenyl linkers efficiently tunes the electron-deficient nature of Pd through the Zr_(6) clusters bridges,which favors the adsorption and activation of the furan ring.Furthermore,the conjugation of different nitrogen-containing ligands facilitates Pd coordination for the Heck-type insertion and subsequent electrophilic palladation,respectively.As a result,the oxidative arylation of FA derivatives is substantially enhanced because of these electronic and steric synergistic effects.Under the optimized conditions,72.2%FA conversion and 74.8%mono aryl furan(MAF)selectivity are shown in the Heck-type insertion.Meanwhile,85.3%of MAF is converted,affording 74.8%selectivity of final product(AFs)in the subsequent electrophilic palladation reaction.This process efficiency is remarkably higher than that with homogeneous catalysts.In addition,furan-benzene polymer obtained from the halogen-free synthesis catalyzed by UiO-67-Pd(F)show significantly better properties than that from conventional Suzuki coupling method.Therefore,the present work provides a new insight for useful AFs synthesis by oxidative arylation of bio-furan via rational tunning the metal center micro-environment of heterogeneous catalyst.
基金allocated by National Science,Research and Innovation Fund(NSRF)King Mongkut's University of Technology North Bangkok(project no.KMUTNB-FF-67-B-44 and KMUTNB-FF-67-B-45)supported by the NSRF through the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(grant no.B40G660036).
文摘This study proposes to use the unconfined compressive strength(UCS)and the bender element(BE)tests for determining the strength and the initial small-strain shear modulus of Bangkok soft marine clay improved by cement and polyester fibers.This study varies the content of admixed cement(1%–20%)and polyester fibers(0–20%),including the curing time(3–28 d)for preparing 360 samples.Moreover,this study uses the Michaelis-Menten kinetics concept to model cement hydration saturation.From the study,it is concluded as follows.The modelled results reveals that at least 10%cement and 1%polyester fiber are recommended to attain the 28-d UCS standards(294 kPa)for highway subgrade materials in Thailand.This also fulfils sustainable construction due to reducing normal-use cement from 20%to 10%.Unfortunately,the addition of polyester fibers into the Bangkok clay with at least 5%cement reduces shear modulus by 1.12–1.32 times.The Abram's relationship between shear modulus and the mixing-water-to-cement ratio is found time-dependent.From the composite theory,the BE detects the polyester fiber zone as a defect in the Bangkok clay(matrix)with 5%–20%cement.So,the 28-d shear modulus in the polyester fiber zone is negative(up to0.034 MPa for 20%fiber),similar to softening phenomenon in concrete cracking(negative stiffness).For the 28-d shear modulus of fiber zone,the optimum cement content is around 2%for the positive influences of polyester fibers.Experimentally,the timedependent normalized UCS for 10%and 20%cement is compatible with other studies,and its development rate increases with the cement content as 0.3017,0.3172 and 0.3204 for 5%,10%and 20%cement,respectively.The 28-d relationship between shear modulus and UCS shows that low-cement soft clay requires high polyester fiber content(5%–20%)to activate UCS improvement.However,the soft clay with enough cement(20%)causes the uniformly distributed UCS improvement.
文摘A series of novel thermotropic liquid crystalline polyesters bearing nonlinear optical azobenzene side group were synthesized by high temperature solution polycondensation and their structures,thermal stability, phase transition behavior and crystallinity were characterized by IR,elemental analysis, TG-DTA, polarizing optical microscope (POM) equipped with a hot stage and X-ray diffraction techniques. The results demonstrate that all the synthesized polyesters exhibit nematic liquid crystalline phases and show relatively high glass transition temperatures and good thermal stability.
基金financial supports from the National Natural Science Foundation of China(Grant No.NSFC52473104)National Key R&D Program of China(Grant No.2022YFC2104500)+3 种基金Zhejiang Provincial Natural Science Foundation of China(Grant No.Y24B040002)Ningbo 2025 Key Scientific Research Programs(Grant No.2022Z160)the China Postdoctoral Science Foundation(Grant No.2023M733601)the Ningbo Natural Science Foundation(Grant No.2023I333&2023J409).
文摘Renewable 2,5-furandicarboxylic acid-based polyesters are one of the most promising materials for achieving plastic replacement in the age of energy and environmental crisis.However,their properties still cannot compete with those of petrochemical-based plastics,owing to insufficient molecular and/or microstructure designs.Herein,we utilize the Ti_(3)C_(2)T_(x)-based MXene nanosheets for decorating carbon nanotube(CNT)and obtaining the structurally stable and highly dispersed dendritic heterostructured MXene@CNT,that can act as multi-roles,i.e.,polycondensation catalyst,crystal nucleator,and interface enhancer of polyester.The biobased MXene@CNT/polybutylene furandicarboxylate(PBF)(denoted as MCP)nanocomposites are synthesized by the strategy of“in situ catalytic polymerization and hot-pressing”.Benefiting from the multi-scale interactions(i.e.,covalent bonds,hydrogen bonds,and physical interlocks)in hybrid structure,the MCP presents exceptional mechanical strength(≈101 MPa),stiffness(≈3.1 GPa),toughness(≈130 MJ m^(-3)),and barrier properties(e.g.,O_(2)0.0187 barrer,CO_(2)0.0264 barrer,and H2O 1.57×10^(-14) g cm cm^(-2) s Pa)that are higher than most reported bio-based materials and engineering plastics.Moreover,it also displays satisfactory multifunctionality with high reprocessability(90%strength retention after 5 recycling),UV resistance(blocking 85%UVA rays),and solvent-resistant properties.As a state-of-art high-performance and multifunctional material,the novel bio-based MCP nanocomposite offers a more sustainable alternative to petrochemical-based plastics in packaging and engineering material fields.More importantly,our catalysis-interfacial strengthening integration strategy opens a door for designing and constructing high-performance bio-based polyester materials in future.
基金from the Special Fund for the Program for Zhejiang Provincial Natural Science Foundation of China(LZ16C160001)National Key Research and Development Program(2017YFD0601105),the National Natural Science Foundation of China(Grant No.21806142)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LY20B070002).
文摘It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranched toughener,carboxylic acid-functionalized tannic acid(CATA),was successfully prepared and applicated to the preparation of solvent-free epoxy resins.The mechanical performance,morphology,structural characterization,and thermal characterization of toughened epoxy resin system were studied.The toughened epoxy resin system with only 1.0wt%CATA reached the highest impact strength,111%higher than the neat epoxy resin system.Notably,the tensile strength and elongation at break of toughened epoxy resin systems increased moderately with increasing CATA loading.Nonphase-separated hybrids with significant toughening effect were obtained.Additionally,the thermal stabilities of toughened epoxy resin systems decreased with increasing CATA loading.This study provides an eco-friendly,cost-effective,and facile approach for the preparation of high-performance,solvent-free epoxy resins with potential for practical applications in sealing integrated circuits and electrical devices fields.
